You might wonder why two railroads as fiercely competitive as the Pennsylvania and the New York Central might agree to streamline their flagship trains simultaneously, with both trains making their debut on the same day: June 6, 1938. Perhaps one answer lies in the fact that, at the time, both railroads leased their sleeping cars from the Pullman company, and the new equipment for both trains was to come from Pullman-Standard. By placing their orders jointly they were able to take advantage of economies of scale and standardization; both sets of equipment would utilize similar mechanicals and floorplans. It was the industrial designers - Raymond Loewy for the Pennsy, Henry Dreyfuss for the Central - which gave the trains their individual personalities.

Both Loewy and Dreyfuss had well earned their outstanding reputations. However, one measure of their results comes from passengers "voting with their feet"; the Broadway's ridership after streamlining remained flat, while the 1938 20th Century Limited routinely ran in two sections to accommodate demand.